Question: What do the following two equations represent? $x+y = 2$ $2x+2y = -2$
Solution: Putting the first equation in $y = mx + b$ form gives: $x+y = 2$ $y = -x+2$ Putting the second equation in $y = mx + b$ form gives: $2x+2y = -2$ $2y = -2x-2$ $y = -1x - 1$ The slopes are equal, and the y-intercepts are different, so the lines are parallel.